Method of and means for measuring the flow of fluids.



M. A. SA'VAGE METHOD OF AND MEANS FOR MEASURING THE FLOW 0F FLUIDS.

APPLICATION FILED FEB. 14. 19M. RENEWED APR. 29. 1915.

Patented Oct. 12, 1915 WZTNE'E'SES MARION A. savanna,

METHOD OF AND MEANS FOR MEASTIRING' THE FLOW OE FLUIDS.

Specification of Letters Patent.

Patented Oct. 12, 1915.

Applicationfiled February t, 1914, Serial No. 818,679. Renewed April 29,1915. Seria1No.'24,79 6.

To all whom it may concern Be it known that I, MARION citizen of theUnited States, residin Schenectady, county of Schenectady,

A. SAVAGE, a at tate 5 of New York have invented certain new and usefulImprovements in Methods of and Means for Measuring the Flow of Flu1ds,

of which the following is a specification.

My intention relates to flow meters for measuring the flow of fluidssuch as steam,

.15 trical conductor, be placed in the path of a flowing fluid andraised to a temperature higher than that of the fluid there will be atransfer of heat from the radiator to thefluid, the amount of which willbe proportional to the difference in temperature between the radiatorand the fluid and to the velocity of flow. -From this it follows thatother things being known, the rate of flow of a fluid may be measured bymeasuring its temperature and its cooling eflect upon a heat radiator.

As is known, the resistance of a conductor is a function of .itstemperature. The relative cooling eflect upon a radiator ,in the 80 formof an electrical conductor can, therefore, be determined by measuring atany instant the. resistance of the conductor. Also the temperature of aflowing fluid can be determined by means of measuring the resist- 85ance of an-electrical conductor exposed to the fluid suchan arrangementamounting in substance to an electric thermometer. By providing,therefore, two electrical resistances one'of-which is heated by anelectric 40' current flowing therethrough to atemperature higher thanthat of the fluid to be metered and exposed to the coolin action 4 ofthe fluid flowing thereover, and t e other of which'is exposed to'andheated by the 46 flowing fluid and measurin the resistances of each, I,can deduce there rom the flow of fluid for any given elocity andtemperature. In other words, they ratio. of the values of the tworesistances to each other,

50 will bear a definite relation to the flow, and

by measuringthis ratio the flow can be read from suitable tables. Insubstance, my improved method comprises measui'ingthe flow of fluid bymeans of measuring the ratio between two resistdiator 3 has a ances, oneof which is heated to a'temperature higher than "that'of the flowingfluid being metered,jand is subjected to the cooling action of .thefluidflowing thereover,

and the other of which is subjected to the temperatureof the fluid.

In carrying out my invention, If use a radiator 111 the form of anelectrlcal resistor heated by an electric current flowing therethrough.This radiator will preferably be of a material having a rather highpositive maybe arranged in the conduit in any approved manner so as tobe fully exposed to the flowlng fluid. In general the flow atall pointsin a conduit is not uniform and for temperature coeflioient ofresistance and.

this reason it is preferredthat the'radiator take a form so as toobtain. as nearly' an average eflect as possible. To this end the samemay be a single conductor extending across the tube or the conductor maycomprise several strands passing back and forth across the tube. Thisradiator will alsoa high temperature coeflicient of resistance and-willbe of such size and resistance that the heating effect of the currentwill be negligible. This resistor may extend across the conduit or beotherwise arranged, it being only essential that it 'be subjected to thetemperature of the fluid to be metered so as to indicate temperaturechanges therein, and be unaffected by convection due to the flowinfluid, I

eferring-now to the drawing whereinI have illustrated my invention,Figure 1 is a view of a diagrammatic nature showing one form "which myinvention may take, and Fig. 2 is a. modification.

preferably be of quite fine wire and high re- I Referring first to Fig.1, the radiator 3 is here shown as asingle electrical resistor extendingsubstantially across a diameter of the conduit 4 through which the fluidto be metered flows. -Adjacent the radiator 3 is a second electricalresistor 5 which acts as the resistance element of an electricalthermometer for indicating the temperature,

this resistor being also shown as a single y conductor. As indicatedinthe drawing the wire and the same are each connected at one end to thecommon connecting post 6 and atthe other end to the conductors 7 and 8respectively, which pass through in- 5 sulating,plugs'9 to the outsideof the condui't. Theseplugs 9 may be each of the same structure, andcomprise essentially a hollow casing 10 threaded into the conduit andfilled witha suitable heat and moisture 10 resisting insulating material11 held in place by the packing gland 12. The outer ends of theconductors 7 and 8 carry suitable binding nuts 13 by means of which thelead wires 14: and 15 are connected. These 15 lead wires may connectwith any suitable ,25 any known or desired means for measuring theresistance of the conductors 3 and 5..

In the present-instance, I have shown an ordinary form of differentialgalvanometer 16 having its respective coils 17 and 18 connected acrossthe members 3 and 5 respectively. The pointer 19 of the galvanometerplays across a scale 20, which scale may indicate in any desired units.example calibrate the apparatus so that the scale will read units offlow directly.

The arrangement shown in Fig. 2 is sub-.

. stantially the same as that shown in Fig.

1, except that the resistors 3 and 5 corresponding to radiator 3 andresistor 5 of 4 Fig. 1, are shown as comprising several turns Theradiator 3 may comprise a .fluid at the temperatureof the fluid.

fluid through a conduit having arranged 2. The method of measuring theflow of thereinv two resistors connected in series, resistances whichare variable in accordance with their temperatures, one having a higherresistance than the other, which consists in passing an electric currentthrough the resistors to raise the resistor of higher resistance to atemperature higher than that of the flowingfluid and measuring the ratiobetween the resistances.

3. Apparatus for measuring the flow of fluid through a conduitcomprising two electical resistors having resistances which are variablein accordance with their tempera tures arranged in the conduit, meansfor passing an electric current through one of said resistors to heatthe same, and means I may 'for number'of turns which will be suitablydistributed'across the tube so'as as give as nearly an average effect aspossible, it be- 4 ing understood that the arrangement of Fig. 2 iswholly diagrammatic.

In accordance with the provisions of the patent statutes, I- havedescribed the principle of operation of my invention, together with theapparatus which I noiv consider to represent the best embodimentthereof; but

i I desire to have it understood that the apparatus. shown is onlyillustrative, and that the invention can be carried out by'other Y 55means.

for measuring the' ratio of the resistance values of said resistors.

4. Apparatus for measuring the flow of fluid through a conduitcomprising a radiator inthe form of an electrical resistor of relativelyhigh resistance, a second electrical resistor of relatively lowresistance, both saidresistors being arranged in said conduit-and havingresistances which are variable in accordance with their temperatures,means for passing an electric current through said first named resistorto heat the same, and means for measuring the ratio of the resistancevalues of said resistors. I

5. Apparatus for measuring the flow of fluid through a conduitcomprising a radiator in the form of an electrical'resistor ofrelatively high resistance, a second electrical resistor of relativelylow resistance, said resistors having resistances which are variable inaccordance with their temperatures and both said resistors beingarranged in said conduit and'connected in series, means 'for" passing anelectric current through said fluid through a conduit" which consists in60 measuring the ratio between two resistors resistors to heat theradiator, and means formeasuring the ratio of saidresistances. Inwitnesswhereof, I have hereunto set my hand this 13th dayof-Febniary,-1951d.

f MARION asavaen. Vlitnesses:

MARGARET-E. WOOLLEY,

, HELEN Onronn.

Correction in Letters Patent N0 1,156,630.'v

It "is hereby certified that in Lettefs Ratent No. 1,156,630; grantedOeteber 12; 1915., epon the application ef Marion AJSztvage) ofSchenectady, New Yerk, forth I improvenie t in Methedsend Meane forMeqshring the Fiowef .Fluidefien error appears in thep rinte'd speei'iicatiolh requix ing eorre cti oh as folldws: Page 2 ,'1ine 71, claim 2,after the word eeries insert the werds and having; and that the said'Letters Patent should be read with this c orrection therein that thesame may eenform'tp the re'eerd 'ef theeese the Pateht Ofii ee.

I Signedfand sealeti: this 9th day ef Novenilber, 13 1,1915.

I J; T. NEWTON,

Acting Oogmwtz'ssz'oner 'Qf Patente.

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